NexSys is a newly established All Island of Ireland Science Foundation of Ireland Strategic Partnership Programme focussed on transitioning to a net zero carbon energy system. It is a unique partnership bringing together a multidisciplinary research team, industry, and policymakers to tackle fundamental research questions to be addressed as part of the transition to net Zero. Hosted by UCD Energy Institute, NexSys brings together academics from nine institutions across the Island of Ireland (UCD, TCD, DCU, ESRI, Maynooth University, UCC, NUI Galway, Ulster University and the Queen's University of Belfast) to work together to meet the unprecedented scale and complexity of the challenges associated with the energy transition.